enable fallocate punch hole ("fallocate -p") for SMB3
Implement FALLOC_FL_PUNCH_HOLE (which does not change the file size
fortunately so this matches the behavior of the equivalent SMB3
fsctl call) for SMB3 mounts. This allows "fallocate -p" to work.
It requires that the server support setting files as sparse
(which Windows allows).
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 3fcd410..101670c 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1015,6 +1015,50 @@
return rc;
}
+static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon,
+ loff_t offset, loff_t len)
+{
+ struct inode *inode;
+ struct cifsInodeInfo *cifsi;
+ struct cifsFileInfo *cfile = file->private_data;
+ struct file_zero_data_information fsctl_buf;
+ long rc;
+ unsigned int xid;
+ __u8 set_sparse = 1;
+
+ xid = get_xid();
+
+ inode = cfile->dentry->d_inode;
+ cifsi = CIFS_I(inode);
+
+ /* Need to make file sparse, if not already, before freeing range. */
+ /* Consider adding equivalent for compressed since it could also work */
+ if (!smb2_set_sparse(xid, tcon, cfile, inode, set_sparse))
+ return -EOPNOTSUPP;
+
+ cifs_dbg(FYI, "offset %lld len %lld", offset, len);
+
+ fsctl_buf.FileOffset = cpu_to_le64(offset);
+ fsctl_buf.BeyondFinalZero = cpu_to_le64(offset + len);
+
+ rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid,
+ cfile->fid.volatile_fid, FSCTL_SET_ZERO_DATA,
+ true /* is_fctl */, (char *)&fsctl_buf,
+ sizeof(struct file_zero_data_information), NULL, NULL);
+ free_xid(xid);
+ return rc;
+}
+
+static long smb3_fallocate(struct file *file, struct cifs_tcon *tcon, int mode,
+ loff_t off, loff_t len)
+{
+ /* KEEP_SIZE already checked for by do_fallocate */
+ if (mode & FALLOC_FL_PUNCH_HOLE)
+ return smb3_punch_hole(file, tcon, off, len);
+
+ return -EOPNOTSUPP;
+}
+
static void
smb2_downgrade_oplock(struct TCP_Server_Info *server,
struct cifsInodeInfo *cinode, bool set_level2)
@@ -1463,6 +1507,7 @@
.validate_negotiate = smb3_validate_negotiate,
.wp_retry_size = smb2_wp_retry_size,
.dir_needs_close = smb2_dir_needs_close,
+ .fallocate = smb3_fallocate,
};
struct smb_version_values smb20_values = {